1. Field of the Invention
This invention relates to a belt buckle or lock for a safety belt having a plug-in passageway in the lock-housing for insertion of a plug-in tongue which can be locked in the housing by a locking mechanism and released by applying pressure to a hand operated member.
2. Description of the Prior Art
In known safety belts having a belt-lock of the above-described type, a locking latch is provided in the interior of a rigid metallic lock housing, which latch is pressed by a spring into the plug-in guide or passageway into which the plug-in tongue is inserted. Usually, the belt-lock is fastened to the frame of the motor vehicle, while the plug-in tongue is secured to the free end of the safety belt, which for example, may be rolled up- and withdrawn from an automatic roll-up device. When the safety belt is put on, i.e. when the plug-in tongue is inserted into the plug-in guide or passageway of the lock-housing, the locking latch engages behind a locking-edge of the plug-in tongue. With a single locking latch, a onesided asymmetrical pull, connected with a more or less strong tilting of the tongue in the plug-in guide results when a load is put on the belt, i.e. in the case of a crash. For this reason it is necessary in such belt-locks to dimension the plug-in path of the tongue, i.e. the guide or passageway of the plug-in tongue, very narrowly and accurately, and to construct the whole lock-housing very solidly, to prevent the destruction or deformation of the belt lock at the occurrence of very strong tilting forces.